1. Field of the Invention
The invention relates to a surgical stapling instrument and more particularly to a surgical stapling instrument for use with a staple carrying cartridge of the type taught in U.S. Pat. No. 4,043,504.
2. Description of the Prior Art
Recently, surgeons have come more and more to the use of staples, rather than conventional thread sutures, for closing wounds or incisions in the skin or fascia of a patient. This trend is due largely to the fact that the use of staples is a far easier procedure and, of even greater importance, is very much faster. This substantially reduces the time required for suturing and the length of time the patient must be maintained under anaesthesia.
Prior art workers have developed various types of surgical stapling instruments and staple cartridges for use therewith, as are exemplified by U.S. Pat. No. RE 28,932; 3,618,842; 3,638,847; 3,643,851; 3,650,453; 3,662,939; 3,717,294 and 3,837,555. The complexity of prior art staple cartridges has been reflected in the complexity and expense of the surgical stapling instruments with which the cartridges are used. The use of complicated gear means or the staple former itself to advance the staples within the cartridge has hitherto required considerable power from the surgical stapling instrument.
The staple carrying cartridge taught in U.S. Pat. No. 4,043,504 constitutes a very much simplier, less expensive and more reliable staple carrying cartridge in which the staples are far less likely to become jammed. The staple carrying cartridge is so arranged that the staple feeding portion of its cycle is completed before the start of the staple forming portion of its cycle.
The surgical stapling instrument of the present invention has been developed specifically for use with the staple carrying cartridge of the above mentioned U.S. Pat. No. 4,043,504. The surgical stapling instrument is provided with a staple forming anvil separate from the staple carrying cartridge. The staple carrying cartridge is mounted on a nose portion of the surgical stapling instrument and means are provided to prevent actuation of the surgical stapling instrument unless and until the staple carrying cartridge is properly mounted on its nose portion. The surgical stapling instrument is provided with a driver and is so constructed as to transmit a manually applied force to the driver so that initial movement of the driver completes the feed cycle of the staple carrying cartridge, further movement of the driver initiating and completing the staple forming portion of the cartridge cycle. A ratchet mechanism is provided in the surgical stapling instrument to prevent reactivation of the staple feed portion of the staple carrying cartridge cycle until the staple forming portion of the staple carrying cartridge cycle has been completed.
The surgical stapling instrument is provided with a latch to maintain the staple carrying cartridge in place on its nose portion. Attachment of the staple carrying cartridge to the instrument nose portion is rendered particularly secure by virtue of the fact that the latch means provides two thrust points, one securely positioning the cartridge with respect to the instrument anvil and the other securely positioning the cartridge against the instrument nose.
The nose portion of the instrument is mounted to the handle portion on resilient bushings so as to be rotatable with respect to the handle portion throughout 360.degree., while maintaining any rotative position with respect to the handle portion to which the nose portion has been set by the surgeon.